Magnetic clutch.



H. W. RAVBNSHAW.

MAGNETIC CLUTCH. APPLICATION FILED rnnzs, 1907.

942, 1 86. Patented Dec. 7, 1909.

2 SHEETS-SHEET 1.

vH. W. RAVENSHAW.

MAGNETIC CLUTCH.

APPLICATION FILED FEB. 28, 1907.

942, 1 86. Patented Dec. 7, 1909.

2 SHEETSSHBET 2.

Uh l'lll SAT PATENT FFFOE.

MAGNETIC CLUTCH.

Specification of Letters Patent.

Patented Dec. '7, 1969.

Application filed February 28, 1907. Serial No. 359,905.

To all whom it may concern:

Be it known that l, HENRY WILLooK RA- vnxsnaw, of Rutland House, Hanwell, in the county of Middlesex, England, have invented new and useful Improvements in Magnetic Clutches, of which the following is a specification.

My invention, by means of which increased efliciency in action is obtained, relates to magnetic clutches of that type in which an annular electromagnet attracts an annular keeper through an intermediate element consisting of two concentric rings of magnetic material attached to each other by a ring of flexible non-magnetic material so that the intermediate element may yield sufliciently to adapt its faces to those of the contiguous parts and to produce, in consequence, a tighter hold when in clutching position.

In order that my invention may be more readily, understood I shall now refer, by

way of types or examples, to certain forms thereof and these 1 illustrate in the accompanying sheets of drawings.

In the drawings,Figure 1 is a, central section of one form of my invention; Fig. 2 is 'a central section of a modification; Fig. 3 shows a detail; Fig. 4: shows an embodiment of my invention in which the driving and driven shafts are parallel; Fig. 5 shows a construction in which the magnetic circuit is completed through a sleeve; and Fig. 6 shows a construction in which the magnetic circuit is completed through the shaft.

Referring to Fig. 1, 1 is the annular trough of magnetic material mounted upon the spider 2 which is keyed to the driving shaft 3, and 4 is the energizing coil. 5 is a hood preferably of non-magnetic material fixed to the periphery of the annular trough i. 6 is a flat rin of magnetic material feathered at its periphery to the hood 5 so as to rotate therewlth but be capable of sliding to and fro in a direction normal to its plane. 7 is an intermediate element consistingrof two concentric rings 8 and9 of magnetic material attached to one another by the ring of flexible non-magnetic material 10. The element 7 is mounted upon the spider 11 which is feathered to the driven shaft 12 so as to slide longitudinally thereon. When current is transmitted through the energizing coil the elements 6 and 7 are pulled to the right and closeup upon the trough, the electromagnetic circuit being through the three elements as shown by the closed dotted line 18. The friction between the contacting surfaces which is largely increased by reason of the tight fit of the parts, made possible by the flexible nonmagnetic ring 10, then causes the shaft 12 to be driven in the usual way.

ln Fig. 2, I show a case which differs from that shown in Fig. 1 in that the number of working faces is increased still further, there being now four intermediate elements 7 7 7 7 of which 7 and 7 are slidably feathered on the shaft 12 and 7 2 and 7" slidably feathered in the-hood 5. in this case the element 6, instead of being feathered in the hood 5 as in Fig. 1, is slidably feathered on the shaft 12. In other respects this case is similar to that shown in Fig. 1 and the flexi-" ble non-magnetic ring again acts to produce a close and tight fit of the parts when closed on each other.

In Fig. 3, I show how the concentric rings 8, 9, may, through the intervention of the rivets 14:, he connected together by the ring of flexible non-magnetic material 10, preferably made of tliin gun metal.

Fig. 4 illustrates a case which differs from those shown in Figs. 1 and 2 in that the driving and driven shafts, instead of being in alincment, are placed side by side. in

thiscase it will be seen that there is no hood 5 but that instead thereof each alternate element gears with a long pinion 15 upon the driven shaft 12. In this case all the elements except the electromagnetic trough slide upon the driving shaft 3.

lln Fig. 5, I illustrate a case which difiers from those previously described mainly in that the magnetic circuit instead of being completed through the inner rings 9 is coinpleted through a sleeve of magnetic material 16. In this case the intermediate elements 7 7 and 7 instead of sliding on the shaft 12 slide upon and are feathered to the magnetic sleeve 16. The magnetic circuit is ifndicated by the closed dotted line 13 as beore.

In Fig. 6, I show another case which differs from those previously described in that the magnetic circuit instead of being com pleted through rings 9, as shown in Figs. 1, 2 and 4-, or through a sleeve of magnetic material, as shown in Fig. 5, is completed through the shaft as indicated by the line 13.- Ihis modification, specifically considered, is however claimed in another ap lication filed March 29, 1909, N 0. 486,610.

I prefer to make the hood 5 of gun metal but I have found that I might even make it of magnetic material although that is disadvantageous.

It is obvious that I may combine two or more of the features hereinbefore specified;

Thus for example I could employ a sleeve 16 in the case where only a single intermediate element is employed as in F ig. 1. Or I might make the elements in Fig. 4 of such shape as to complete the magnetic circuit through the driving shaft 3. Or I could place the driving and driven shafts parallel to one another with other forms of elements, and with other courses of magnetic circuits, than as shown in Fig. 4.

It will be obvious that the driving and driven shafts can be made interchangeable and that I might compose my clutch of an element" fast on one shaft, an element loose on that shaft, one or more intermediate elements and a gear fast on the other shaft.

I claim,

1. A magnetic clutch comprising a driving and driven shafts, an annular electromagnet and an annular keeper, and an intermediate element consisting of two concentric rings of magnetic material secured together by a flexible ring of non-magnetic material, whereby a ti hter fit between the parts of the clutch wien in operation is effected, substantially as described.

2. A magnetic clutch comprising a driving and driven shafts, an annular electr0- magnet and annular keeper, an intermediate element consisting of two concentric rings of magnetic material secured together by a flexible ring of non-magnetic material, and a sleeve of magnetic material surrounding the shaft, the magnetic circuit from the magnet to the keeper being completed out through the intermediate element and back through the sleeve, substantially as described.

3. A magnetic clutch comprising an annular electromagnet and an annular keeper, an intermediate element consisting of two concentric rings of magnetic material socured together by a flexible ring of nonmagnetic material, the outer ring being supplied with gear teeth, and a driving and a driven shaft one of which carries a pinion meshing with the teeth described, substantially as described.

In witness whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HENRY WILLOCK RAVENSHAW.

Witnesses:

H. D. JAMEsoN, IT L. RAND. 

